Secure Mounting of Excavation Equipment Teeth

ABSTRACT

A replaceable wear point of excavating equipment, such as a tooth of an excavator bucket, is mounted on the bucket&#39;s nose piece using a conventional fastener arrangement plus an adhesive, preferably epoxy, injected into the tooth pocket to fill a gap between the nose piece and the tooth pocket. For injecting the epoxy, a hole is preferably formed through the tooth to communicate into the bottom of the tooth pocket. The injected epoxy preferably squeezes out of the tooth pocket opening and is smoothed to form an epoxy fillet along the junction of the tooth and the nose piece. The epoxy fills gaps, holds the tooth tight against wiggling on the nose piece, and seals out grit and water, to prevent or reduce interior wear of the tooth pocket and the nose piece, and to prevent or delay the tooth from falling off the nose piece.

FIELD OF THE INVENTION

The present invention relates to a method, an arrangement and acombination of components for securely mounting replaceableground-engaging wear points, called teeth herein, of ground-engagingtools of excavating equipment.

BACKGROUND INFORMATION

Excavating equipment is used in various industries, such as mining,quarrying, dredging, road building, landscaping, commercial andresidential building construction, and various other constructionindustries, for digging holes, trenches, tunnels, etc., for breaking-up,loosening and removing soil, gravel, rocks, ore, coal and other groundmaterials, and for loading such materials into further earth movingequipment. Such excavating equipment includes hydraulic excavators,backhoes, bucket loaders, skid-steer loaders, bucket and rotarydredgers, earth boring drills, excavation drag lines, cable shovels,face shovels, clam shell buckets, ground rippers and the like. All ofsuch equipment includes a ground-engaging tool, such as a digging orloading bucket in the case of an excavator, backhoe, bucket loader andthe like, for example. The ground-engaging tool has a forward edge forcutting or digging the ground, and is further provided withground-engaging wear points typically called teeth. These teeth aresubject to extreme wear, due to digging, scraping and prying in soil,gravel, rocks, broken concrete, and other coarse, abrasive, hardmaterials. For this reason, the teeth are typically removably mounted onthe bucket, so that the teeth can be replaced when they are worn beyonda serviceable range. In this regard, each tooth typically has a toothsocket or pocket therein, which is mounted on a nose piece, which inturn is connected to the front edge of the bucket by welding or bolting.Alternatively, some tooth-mounting nose pieces are formed as a permanentcomponent, being forged or cast together with the front digging edge ofthe bucket. In some cases, an additional adapter piece is interposedbetween the nose piece and the tooth, for example in order to use adifferent brand, size or style of tooth in comparison to the design ofthe nose piece. The nose piece itself is sometimes also referred to asan adapter or as a shank, on which the tooth is to be mounted. In thepresent application, the term “nose piece” is used generally, broadlyand inclusively to include all manner of known nose pieces, shanks andadapters on which replaceable teeth are to be mounted, and the term“tooth” is used generally, broadly and inclusively to include all mannerof known replaceable, ground engaging, wear points of excavatingequipment.

A nose end of the nose piece is shaped to mate approximately or coarselywith the interior dimensions and configuration of the pocket in thetooth. The tooth is mechanically secured on the nose piece by a toothfastener arrangement, of which there are many different types known inthe prior art. The tooth fastener arrangement typically includes afixing pin or clip that extends through a hole provided in alignmentthrough the tooth and the nose piece. This fixing pin and the hole forreceiving it may extend transversely side-to-side or front-to-back orupwardly/downwardly through the tooth and nose piece in differentdesigns of fastener arrangements. The fastener arrangement typicallyadditionally includes a keeper or retainer that retains the fixing pinin the aligned holes of the tooth and the nose piece. In this regard,conventionally known tooth fastener arrangements include a flex pinincluding steel pin members and a rubber keeper, a spring pin, a fixingpin and split washer, a bolt and nut combination, a pin and retainerlock, a horseshoe locking clip, a roll pin, a grooved pin, a crimp-onretainer, a pin and plug combination, and various others. While thesefastener arrangements are intended to hold the tooth on the nose pieceand transfer digging forces from the tooth into the nose piece (inaddition to the force-transferring contact of the nose piece in thetooth pocket), there are always remaining gaps between the tooth and thenose piece in the tooth pocket, and the tooth is always slightly looseon the nose piece. This is true especially after the tooth has been inuse for digging, resulting in wear and looseness of the tooth. Thus, thetooth can be felt to “wiggle” slightly on the nose piece, for examplepivoting slightly around the fixing pin of the fastener arrangement.Such slight wiggling looseness of the teeth on the nose pieces ispresently regarded as acceptable field performance, as long as thefastener arrangement holds the tooth on the nose piece and the tooth issufficiently supported on the nose piece to withstand the diggingforces.

However, whenever the tooth can wiggle or move back and forth on thenose piece, this causes chafing wear of both the nose piece and theinterior surfaces of the tooth pocket. As a result, the fit of the toothbecomes ever looser on the nose piece, which causes the wear to progresseven more rapidly. Furthermore, when the teeth and bucket (or otherground-engaging tool) are digging in sand, soil or gravel, smallabrasive particles of the ground material easily enter the gaps betweenthe tooth and the nose piece in the tooth pocket, and these particlesfurther abrasively accelerate the wear of the nose piece and the toothpocket. The interior wear becomes especially significant when digging inloose sandy or gritty soil, because the sand or grit gets into the gapsbetween the nose piece and the interior of the tooth pocket and causessignificant interior wear, while the exterior wear of the tooth is lessin such soil than in hard rocky gravel or broken rock. Still further,water penetrates into the gaps between the nose piece and the tooth inthe tooth pocket, and causes rapid rusting corrosion of the worn metalof the nose piece and the tooth in the pocket. These factors all combineto accelerate the wear and the loosening of the tooth.

Finally, the tooth can become so loose that the fastener arrangement canno longer hold it, for example because the elastic or resilient range ofthe keeper device does not extend as far as the wear has progressed, sothat the keeper loses its resilient keeping function. The fastener pinthen falls out and the tooth falls off the nose piece during a diggingoperation, whereby the tooth is generally lost in the soil or otherground material.

Such teeth can range in size from about the size of a man's fist toabout the size of a man's torso, and can range in price from about fiftyto several hundred dollars. During each week of full time diggingoperation, an excavation contractor operating several excavationmachines may need to replace several teeth that have been lost or thathave excessive interior wear and looseness, so that the costs ofreplacing lost or worn teeth can become substantial. This is especiallyproblematic when a tooth has become loose and/or has fallen off the nosepiece even though the exterior dimensions and configuration of the toothare still within a serviceable range. Furthermore, if the nose piecebecomes significantly worn, then the nose piece itself should also bereplaced, which involves a significant replacement part cost and alsosignificant labor costs. The nose piece especially becomes rapidly wornif digging continues after a tooth is lost.

When a brand-new tooth is mounted on a brand-new nose piece or shank ona new excavator bucket, depending on the type and size of tooth, thefull exterior wear operating life of the tooth might be expected to bein the range of 1000 to 1500 hours, on average, when digging in atypical mixture of soil conditions, but could be only in a range of 600to 800 hours when digging mostly in rocky gravel or rocks. The aboverefers to the exterior wear of the cutting, digging and scrapingsurfaces of the tooth. On the other hand, under good conditions theinterior wear inside the tooth pocket and on the nose piece is generallynot expected to be as severe and rapid, so that a nose piece may beexpected to have an expected operating life of about 3000 hours as arough average, with a great range of variation depending on the nosepiece type and dimensions, the particular machine, the particular nosepiece material, the ground type being worked, etc. A typical excavationmachine being operated essentially full time by an excavation contractorin New England might be expected to accumulate about 1500 or 1600 hoursof operating or digging time per year. Thus, such a machine might needone or two sets of teeth per year in view of the maximum exterior wearservice life. But many teeth that have only about 50% exterior wear arenow typically being discarded and replaced with new teeth, simplybecause of looseness of the tooth on the nose piece due to the interiorwear of those parts. If operated further, such loose teeth often falloff anyway if they are not replaced. For example, it has been observedthat teeth fall off and are lost after as little as about 400 hours ofoperation, due to interior wear and looseness of the tooth on the nosepiece. For the above reasons, excavation contractors and otherexcavation equipment operators are suffering significant additionalcosts in replacing teeth that have been lost due to falling off, or thathave become too loose on the nose piece due to interior wear, eventhough the exterior of the tooth would still have provided additionalservice life.

It has thus long been desired in the field of excavation, to provide anarrangement and/or method by which a replaceable tooth can be secured ona nose piece in such a manner to avoid the wiggling looseness of thetooth on the nose piece as described above, to avoid interior wear ofthe tooth pocket and the nose piece, and preferably to avoid thepenetration of sand or other grit and water into any gaps between thenose piece and the tooth pocket. The prior art has generally tried toincrease the security and improve the ease of installation of the toothfastener arrangements, which has given rise to many different styles offastener arrangements as mentioned above. Those approaches, however, donot resolve or even address the above mentioned problems of interiortooth pocket and nose piece wear, looseness of the tooth and penetrationby grit and water. It is also conventionally known to provide a dirtshield collar around the base of an adapter to keep dirt out of or awayfrom a receiving socket for the adapter, and/or to provide a weld beadto secure an adapter in a socket, or to provide an o-ring seal between atooth pocket and a nose piece in order to try to keep dirt from enteringthe pocket. Such efforts have only been partially successful ataddressing the above problems, so that further improvements are desired.

SUMMARY OF THE INVENTION

In view of the above, it is an object of the invention to provide amethod, an arrangement, and a combination of components for securelymounting a replaceable ground-engaging wear point or tooth on atooth-receiving nose piece of a powered ground-engaging tool such as abucket of excavating equipment. It is a particular object of theinvention to fill and seal existing gaps between the nose piece and theinterior of a tooth pocket so as to prevent the penetration of gritparticles and water. It is a further object of the invention to securelyadhesively bond the tooth onto the nose piece by an adhesive that fillsgaps between the nose piece and the tooth in the tooth pocket. Anotherobject of the invention is to provide a method and tools by which such asecure mounting of teeth can be performed easily and at relatively lowcost in the field, with minimal down-time of the excavating equipment.The invention further aims to provide a method and components forrefurbishing loose worn teeth on excavating equipment in the field.Another goal of the invention is to reduce or avoid the loosening andloss of teeth from excavating equipment while the teeth are still withintheir usable service life. Still further, the invention aims to avoid orovercome the disadvantages of the prior art, and to achieve additionaladvantages, as will be apparent from the present specification. Theattainment of these objects is, however, not a required limitation ofthe claimed invention.

The above objects have been achieved according to the invention, whereinan adhesive and preferably a thermosetting epoxy adhesive is disposed inan existing gap between the nose piece and the interior of the toothpocket during the process of mounting the tooth on the nose piece. Theepoxy is allowed to cure, thereby hardening and adhesively bonding thetooth onto the nose piece, in addition to the mechanical connectionprovided by the tooth fastening arrangement. Preferably, the epoxysubstantially fills the existing void volume of the gap or gaps betweenthe nose piece and the tooth pocket, for example filling at least 75% ofthe void volume, or more preferably at least 90% or even more preferablyat least 95% of the void volume. Further preferably, the epoxy isprovided in such an amount so that it squeezes out of the opening of thetooth pocket around the shaft or shank of the nose piece, and issmoothed off there to form an epoxy bead or fillet, which seals the gapand prevents the penetration of grit and water. After the epoxy hascured, the epoxy holds the tooth securely and firmly on the nose piece,and prevents wiggling or looseness of the tooth on the nose piece. Whilemost of the digging forces acting on the tooth are transmitted from thetooth directly into the nose piece by direct metal-to-metal contact ofthe tooth pocket on the nose piece (preferably at least 50% of the nosepiece surface area within the tooth pocket is in direct metal-to-metalcontact with the tooth), the epoxy also helps to transmit and distributethe loads through additional surface areas that otherwise (withoutepoxy) would have been open air gaps allowing wiggling looseness of thetooth. Thereby, the epoxy essentially completely stops corrosive,erosive, abrasive and chafing wear of the nose piece and the interior ofthe tooth pocket during the operating service life of the epoxy.

One method of providing the epoxy involves mixing the two components ofthe epoxy material to form a viscous activated epoxy liquid or paste,which is poured or injected or applied into the tooth pocket beforemounting the tooth on the nose piece. The volume of epoxy to be usedmust be estimated, so that when the tooth is slid and pressed onto thenose piece, the epoxy will squeeze up and out of the tooth pocket aroundthe shaft or shank of the nose piece, without having excessive overspillof epoxy. A further improved and preferred method involves forming ahole through a solid wall of the tooth, at a location to communicateinto the blind bottom of the tooth pocket, e.g. preferably directly ator adjacent to the blind bottom of the tooth pocket, or generally withinthe gap area between the terminal nose end of the nose piece and thedeepest blind bottom of the tooth pocket, or more generally within thedeepest 25% or preferably 15%, or 1.5 inches or preferably 1 inch of thedepth of the tooth pocket. Then, epoxy is injected, preferably from atwo-component epoxy cartridge using a suitable two-component applicatorgun, through a mixing tube and a nozzle adapter tip, via the providedepoxy injection hole into the tooth pocket after the tooth has beenmounted on the nose piece. The epoxy is thereby injected and flows underpressure into the void space or gap between the nose piece and theinterior of the tooth pocket, and flows around and upwardly along theshaft or shank of the nose piece through any existing void channelsuntil the epoxy squeezes out at the opening of the tooth pocket aroundthe nose piece shaft. The epoxy injection hole is preferably located ator sufficiently close to the blind bottom of the tooth pocket so thatthe injected epoxy will flow into all or substantially all areas (e.g.at the bottom corners) of the gap or void space in the tooth pocket,while filling these areas and flowing upwardly to push out air and notentrap a substantial volume percentage of air bubbles or air pockets.Epoxy is preferably also injected into the fastener hole, before orafter installing the fastener arrangement, so that the epoxy alsosecures the fastener arrangement and seals the fastener hole againstpenetration of grit and water.

The invention further preferably provides a clamp fixture or holding jigfor holding and tightening a tooth in position after the epoxy has beeninjected, to ensure the tightest possible metal-to-metal contact betweenthe tooth and the nose piece, and to hold the arrangement firmly andsecurely during the curing of the epoxy.

Further preferably according to the invention, the nose piece and theinterior of the tooth pocket are cleaned before mounting the tooth andinjecting the epoxy, for example including a degreasing treatment with asuitable solvent to remove any grease, oil, grime, dirt etc., followedby a mechanical abrasive cleaning with a wire brush, needle scaler orsand or grit blasting equipment to clean the surfaces to bare metal androughen the surfaces for improved adhesive bonding by the epoxy.

BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be clearly understood, it will now beexplained in further detail in connection with example embodimentsthereof, with reference to the accompanying drawings, wherein:

FIG. 1 is a generalized schematic perspective view of an excavatorbucket with replaceable teeth mounted on nose pieces thereof;

FIG. 2 is a schematic perspective view of a representative example of adigging tooth, a nose piece, and a tooth fastener arrangement, whereinthe tooth, nose piece and fastener arrangement may be any conventionallyknown types of such components, but the tooth has been modifiedaccording to the invention with an epoxy injection hole;

FIG. 3 is a schematic cross-sectional view of the tooth mounted on thenose piece with the installed fastener arrangement, and with epoxyinjected into the epoxy injection hole to substantially fill any gap orvoid space between the nose piece and the interior of the tooth pocket;

FIG. 4 is a schematic diagram of a clamping fixture or holding jigaccording to the invention, for tightly clamping the teeth and holdingthe teeth in position while the epoxy cures; and

FIG. 5 is a schematic diagram representing steps of a preferred methodaccording to the invention.

DETAILED DESCRIPTION OF PREFERRED EXAMPLE EMBODIMENTS AND THE BEST MODEOF THE INVENTION

FIG. 1 schematically illustrates a typical small excavator bucket 1, asa representative example of a powered ground-engaging tool of excavatingequipment. The present invention is not limited to excavator buckets,but rather applies to all powered ground-engaging tools of allexcavating equipment, having replaceable ground-engaging wear points,such as the representative teeth 2 mounted on the bucket 1.Particularly, the teeth 2 are mounted on nose pieces 4, which areconnected to the front digging edge 3 of the bucket 1. The nose pieces 4may be bolted or welded onto the separate digging edge 3, or may beformed as an integral part of the digging edge 3. The nose pieces 4generally represent any conventionally available nose pieces, shanks oradapters onto which replaceable teeth 2 or ground-engaging wear pointsare to be mounted. Sometimes the nose piece includes a first base piecethat is connected to the digging edge 3 of the bucket 1, and a secondadapter piece that is mounted on the base piece, for the particular typeof tooth 2 to be mounted on the adapter. The term “nose piece” is usedbroadly and inclusively herein to cover all one-piece and multi-piecearrangements for receiving a tooth thereon. Each tooth 2 is mechanicallyfastened on the respective nose piece 4 by a tooth fastener arrangement5, as will be discussed below.

The arrangement as shown in FIG. 1 is generally representative ofconventional excavation buckets and teeth, except that the teeth andtheir mounting arrangement have been modified according to theinvention. Namely, each tooth 2 has been provided with an epoxyinjection hole 9, and epoxy 11 has been injected through the hole 9 soas to substantially fill any void space or gap between the nose piece 4and the interior of the tooth pocket mounted on the nose piece, untilepoxy squeezes out of the tooth pocket to form an epoxy squeeze-out beador fillet 12 around the neck or shank of the nose piece 4. Suchsqueeze-out of the epoxy is not mandatory, but helps to prevent thepenetration of water and grit into the tooth pocket. In addition to thetooth fastener arrangement 5, the epoxy 11 helps to secure the tooth 2on the mounting nose 4, helps to transmit and distribute the forcesbetween the tooth 2 and the nose piece 4 in addition to the directmetal-to-metal contact of the nose piece 4 in the tooth pocket, preventsloose wiggling of the tooth 2 on the nose piece 4, and prevents orreduces the penetration of grit and/or water into the tooth pocket.These functions and features avoid or reduce the interior wear insidethe tooth pocket and on the nose piece, and thereby extend the operatinglife of the tooth 2 by avoiding or delaying the looseness andfalling-off of the tooth. This achieves a significant cost savings forthe excavation equipment operator, because the teeth 2 can be used fortheir full exterior wear life before needing to be replaced.

FIG. 2 schematically shows a representative example of a replaceabletooth 2, a nose piece 4, and a tooth fastener arrangement 5. The nosepiece 4 has a mounting slot 4B that is mounted on the front digging edge3 of the bucket 1, and then is secured by welding. The nose piece 4further has a nose end 4A onto which a tooth pocket 2A of the tooth 2 isto be mounted. The nose end 4A of the tooth mounting nose piece 4 isdimensioned and shaped to be received in the tooth pocket 2A of thetooth with a substantially snug fit. Nonetheless, in view of the sizeand relatively rough or coarse nature of these components, it isunavoidable that some gap or void space will always exist between thenose piece 4 and the interior of the tooth pocket 2A, due tomanufacturing tolerances and the need for some clearance to easeinstallation.

After the tooth 2 has been mounted on the nose piece 4, i.e. the noseend 4A has been received in the tooth pocket 2A, the tooth is fastenedby the fastener arrangement 5. There are many different types of toothfastener arrangements conventionally available on the market, and thepresent invention applies to all of such different fastener types. Thefastener arrangements typically include a metal fixing pin thatmechanically fixes the tooth to the nose piece, and a keeper or retainerthat keeps or retains the fixing pin 6 in place. In the simple exampleillustrated in FIG. 5, the tooth fastener arrangement 5 includes twometal fixing pins 6, with an elastic rubber keeper 7 sandwichedtherebetween. This arrangement 5 is driven laterally through alignedfastening holes 8 provided in the tooth 2 and the nose piece 4. Therubber keeper 7 compresses as the pin is driven into the holes 8, andthen expands to keep the pin seated in the holes 8 once the pin is fullyinserted. The resilient elastic expansion of the rubber keeper 7 alsoexpands the fastener arrangement 5 in the aligned holes 8 to maintainthe tooth pocket 2A snugly seated onto the nose piece 4. However, duringdigging operations, the strong pivoting, torquing and sliding forcesapplied to the tooth 2 also exert corresponding forces on the fastenerarrangement 5, whereby the elastic rubber 7 compresses and allows somepivoting or wiggling and sliding of the tooth 2 on the nose piece 4.This movement of the tooth 2 on the nose piece 4, together with theexisting gaps or void spaces as mentioned above, causes chafing wear onthe interior of the tooth pocket 2A and the exterior of the nose piece 4within the tooth pocket. Furthermore, this allows the penetration ofwater and grit into the existing gaps or void spaces, which producescorrosive, abrasive and erosive wear in addition to the metal-to-metalchafing wear mentioned above. As a result, the tooth 2 would become everlooser on the nose piece 4 until it is no longer serviceable for diggingoperation, or even until it can no longer be held on the nose piece 4 bythe fastener arrangement 5, whereupon the fastener arrangement 5 fallsout of the aligned holes 8 and the tooth 2 falls off of the nose piece 4and is lost during the digging operation.

To avoid the above described wear and the resulting loss of the tooth orpremature maintenance need to replace the tooth, the invention mountsthe tooth 2 on the nose piece 4 with an adhesive in addition to theconventional mounting with the fastener arrangement 5. In this regard,the tooth 2 is provided with at least one adhesive injection hole 9 thatcommunicates from the outside of the tooth into the tooth pocket 2A, aswill be further discussed next.

FIG. 3 is a schematic cross-sectional view of the tooth 2 mounted andsecured on the nose piece 4 according to the invention. The arrangementis shown in a preferred tooth down orientation of the excavator bucketfor carrying out the tooth mounting operation according to theinvention. The bucket 1 itself is omitted from FIG. 3 for simplicity,but it should be understood, in the condition shown in FIG. 3, that thenose piece 4 would already be mounted and welded onto the front diggingedge 3 of the bucket 1 received in the mounting slot 4B of the nosepiece 4.

As shown in FIG. 3, a void space or gap 10 exists between the nose piece4 and the interior walls of the tooth pocket 2A of the tooth 2,especially at the forward terminal end of the nose end 4A of the nosepiece 4. But this gap or void space 10 also continues along gap channelsbetween the walls of the tooth pocket 2A and the nose piece 4 all theway to the opening of the tooth pocket 2A at the rear or upper end ofthe tooth 2. While FIG. 3 shows a continuous gap extending all the wayalong the walls of the pocket 2A, it should be understood that most ofthe surface area of the flat surfaces of the body or shank of the nosepiece 4 inserted into the tooth pocket 2A is in direct metal-to-metalcontact with the flat inner walls of the tooth pocket 2A, especiallyassuming that a new unworn tooth is being mounted on a new unworn nosepiece. Even with such new components, however, there will always be somesmall gaps or void space channels, for example especially along edgesetc., in view of manufacturing tolerances, and the need of someclearance to facilitate the insertion of the nose piece 4 into the toothpocket 2A. If the tooth 2 and/or the nose piece 4 is already somewhatworn through use, then the gaps or void spaces become larger and moreprevalent.

According to the invention, the void space or gap 10 has beensubstantially or entirely filled with an adhesive, and preferably athermosetting, curable, two-component epoxy 11. Methods for achievingthis will be described in detail below. Generally, a preferred methodinvolves providing at least one epoxy injection hole 9 through at leastone wall of the tooth 2 so as to communicate into the tooth pocket 2Aat, adjacent to or near the deepest point in the tooth pocket 2A, i.e.at, adjacent to or near the blind bottom of the tooth pocket 2A. Forexample, this preferably involves forming the hole 9 at a location sothat it communicates into the gap or void space 10 between the terminalend of the nose end 4A of the nose piece 4 and the deepest bottom of thetooth pocket 2A, or preferably within the deepest 25% or 1 inch of thelength or depth of the tooth pocket 2A, or most preferably adjoining thevery bottom of the tooth pocket 2A. The epoxy 11 is injected underpressure to fill the gap 10 at the furthest bottom of the tooth pocket2A and also extending upwardly along the sides of the tooth pocket 2A,until the epoxy squeezes out and is preferably smoothed off to form abead or fillet 12 of epoxy at the opening of the tooth pocket 2A aroundthe body or shank of the nose piece 4. The bead or fillet 12 of epoxycan alternatively or additionally be externally applied in an extrastep. Epoxy 11 is preferably additionally injected into the alignedholes 8 to surround the fixing pins 6 and keeper 7 of the tooth fastenerarrangement 5, thereby preventing elastic yielding compression of thisfastener arrangement and further rigidly holding the tooth 2 on the nosepiece 4. The epoxy, preferably filling all voids or gaps 10 around thenose piece 4 in the tooth pocket 2A, serves to securely and fixedly holdthe tooth 2 on the nose piece 4 to prevent looseness, wiggling or anyother motion of the tooth 2 relative to the nose piece 4. The epoxy alsodistributes and transmits the forces between the tooth 2 and the nosepiece 4, in addition to the areas of direct metal-to-metal contactbetween the tooth 2 and the nose piece 4. The void-filling epoxy 11, andespecially also the bead or fillet 12 of epoxy further serves to preventor minimize the penetration of grit and/or water into the tooth pocket2A around the nose piece 4. The above functions together completelyprevent or significantly minimize interior wear of the tooth pocket 2Aand wear of the nose piece 4 within the tooth pocket 2A, including theabove discussed chafing wear, corrosive wear, erosive wear, and abrasivewear. The ultimate effect of the inventive provision of the epoxyadhesive is to prevent or delay the time at which a tooth needs to bereplaced due to interior wear or the time at which a tooth falls off andis lost.

Methods of mounting and securing the tooth will now be described inconnection with FIG. 5. It should be understood that FIG. 5 merelyschematically illustrates one possible order or sequence of steps, anddifferent sequences or orders of the various steps are also possible andsuitable within the scope of the present invention. Furthermore, some ofthe steps indicated in FIG. 5 are optional and may be entirely omitted,and some of the indicated steps can be replaced by alternatives. Themethods according to the invention can be applied to used worn teeth andnose pieces, as well as new teeth and nose pieces, as well as new teethon worn nose pieces or worn teeth on new nose pieces.

In a most basic method according to the invention, the indicated stepsS1, S2, S3, S5, S7, S8 and S9 can be omitted as unnecessary or notmandatory, and instead of step S5, the epoxy material is simply pouredor injected or applied into the tooth pocket of the original unmodifiedtooth before the tooth is mounted on the nose piece. Such a simpleembodiment of the method proceeds as follows. The two components of theepoxy material are measured or dosed and mixed in the appropriateproportions, for example 1:1. The resulting activated epoxy material isthen injected, poured or troweled into the tooth pocket of the tooth.The volume of the epoxy material to be applied is estimated based on thevolume or size of the gap between the free terminal end of the nosepiece and the deepest extent of the tooth pocket as well as additionalgap spaces around the sides of the nose piece. An additional amount ofepoxy should also be provided to ensure that epoxy will completely fillvoid spaces and also squeeze out. The excavator bucket is positionedsafely in a tooth down orientation, with a bare exposed nose piece. Theepoxy-filled tooth pocket is then moved upwardly onto the nose piece inone smooth motion so that the nose piece smoothly submerges into theepoxy and the epoxy squeezes upwardly around the nose piece in the toothpocket, without creating air bubbles, air pockets or gaps in the epoxy.Once the tooth is fully pushed onto the nose piece, then the fastenerarrangement such as a fixing pin and a keeper are installed in the usualmanner. The fastener arrangement mechanically holds the tooth tightly onthe nose piece until the epoxy cures. Then the excavation equipment maybe used in the normal manner.

Further preferred features and steps according to the invention arepreferably added to, or substituted in, the above most basic embodimentof the inventive method, as follows. As indicated by steps S1 and S5 inFIG. 5, rather than pouring, injecting or troweling the epoxy materialinto the tooth pocket before installing the tooth on the nose piece, theinventive method preferably involves injecting epoxy material through aninjection hole 9 in the tooth 2 after the tooth has been mounted on thenose piece 4. In this regard, present commercially available teeth donot have such injection holes, so that an injection hole 9 must first beformed in the tooth according to step Si. For a relatively smallinexpensive tooth made of plain steel or only minimally hardened steel,the epoxy injection hole 9 can be drilled with a hardened drill bit suchas a carbide bit or a cobalt bit. On the other hand, a large hardenedmetal tooth 2 cannot be drilled by hand, but instead must be drilledwith an appropriate hardened bit in a boring or machining center.Alternatively, if such a machining center is not available, or forin-the-field work, the epoxy injection hole 9 is formed by burning thehole through the hardened tooth material with a torch, such as anoxygen-acetylene torch or other high temperature torches. The epoxyinjection hole 9 is located as described above with reference to FIG. 3.The hole 9 can be provided through any one or more sides of the tooth soas to reach and communicate into the tooth pocket as described above,but for easy access it is presently preferred to make the hole 9 on thefront digging face of the tooth as shown in FIG. 3. The hole canalternatively be provided on the back face or on the side faces of thetooth. Depending on the size and the configuration of the void space orgap 10, it is further advantageous to provide more than one epoxyinjection hole, to ensure that epoxy 11 reaches and fills all spaces andgaps, but typically a single injection hole 9 is sufficient. Preferablythe diameter of the hole 9 is in the range from ¼ inch to ⅜ inch, orparticularly preferably about 5/16 inch, but generally the hole (orholes) can be any size suitable for receiving an adhesive injectionnozzle. If the hole 9 is formed by burning or boring with a torch, thenthe surface of the tooth around the hole is preferably ground flat withan abrasive grinder after forming the hole. Also, if the hole 9 isformed with a torch, care should be taken not to overheat the entiretooth or especially the cutting end thereof, so that the hardened stateof the metal is not altered, and/or after forming the hole the hot toothshould be quenched in water to ensure that the metal is appropriatelyhardened. Ultimately, it is intended that manufacturers of replaceablewear teeth will provide appropriate epoxy injection holes in the teethas originally manufactured, so that the epoxy injection hole 9 isalready pre-existing and does not need to be formed (bored, burned,etc.) in the field.

Step S2 in FIG. 5 represents an additional optional step or group ofsub-steps to clean the tooth pocket and the nose piece. Such proceduresare preferred to achieve the best adhesive bond between the tooth 2 andthe nose piece 4. The cleaning procedures S1 include a first sub-step ofremoving any loose dirt and the like, for example with a stiff brushand/or a water spray. The cleaning step S2 further preferably involves adegreasing sub-step, of washing both the tooth pocket and the nose piecewith a suitable solvent for removing any grease, oil etc., whereby thesolvent may involve soap or detergent in water, mineral spirits,turpentine, alcohol, gasoline, acetone, and/or any other solventsuitable for removing the contaminants on the metal of the tooth pocketand the nose piece. The cleaning step S2 further preferably includes athird sub-step of an aggressive mechanical abrasion and cleaning tobring the mating surfaces of the tooth pocket and the nose piece down tobare metal and to roughen the metal surfaces, for enhancing the adhesionof the epoxy. This process removes any rust, dirt, scale, paint or othercontaminants or surface coatings that might be on the tooth pocket andthe nose piece. This procedure is carried out preferably by sandblastingor grit blasting with coarse grade blasting media such as coarse BlackBeauty™ blasting sand. Alternatively, this process can be carried outwith a pneumatically powered needle scaler, or as a further alternativewith a wire brush wheel on a powered grinder. This cleaning procedure S2can be performed before or after the step S1 of forming the epoxyinjection hole, or is performed on the tooth pocket of a tooth thatalready previously has the epoxy injection hole therein.

If the nose piece is new and unworn, or not significantly worn, then theindicated step S3 is not necessary. On the other hand, if the nose piece4 is significantly worn, then it is preferred to build-up the worn areasof the nose piece by hard face welding or deposit welding, and thengrind the built-up areas to re-shape the nose piece as close as possibleto the proper like-new dimensions and configurations, so as to snuglyreceive the tooth 2 thereon, i.e. to snugly fit into the tooth pocket2A. This improves the direct metal-to-metal force transmission from thetooth to the nose piece, and enhances the durability of the epoxy.

Next, according to the step 54 as indicated in FIG. 5, the tooth ismounted on the nose piece, simply by inserting the nose end 4A of thenose piece 4 into the tooth pocket 2A, by pushing the tooth 2 upwardlyonto the downwardly oriented nose piece 4.

The next preferred but optional step is to inject epoxy into the toothfastener hole 8 in the assembled and aligned tooth 2 and nose piece 4,as indicated by step 55 in FIG. 5. Then, the tooth fastener arrangement5 is installed into the hole 8 in the normal manner, as indicated bystep S6. This will typically push some of the epoxy out of the hole 8,but also embeds the fastener arrangement in the epoxy 11 remaining inthe hole 8. After installing the fastener arrangement 5, additionalepoxy can be injected around the fastener arrangement in the hole 8.Step S5 can alternatively be performed entirely after step S6.

Next, according to the step 57, epoxy is injected through the injectionhole 9 into the tooth pocket 2A. This is preferably achieved using atwo-component injection gun, such as a caulking gun made fortwo-component material cartridges. One preferred gun for this purpose isthe MixPac™ Type DM 400™ dual cartridge gun. Rather than this manuallyoperated gun, a further preferred electrically operated gun is theElectraflow 400 MR™ from Cox Applicators. Each one of these guns acceptsa dual cartridge or two-component dual chamber cartridge of the twocomponents of an epoxy adhesive, and ejects the two components at theappropriate ratio, e.g. 1:1, thereby avoiding operator error in thedispensing or proportioning of the epoxy components. Furthermore, theapplicator gun is fitted with a mixing nozzle tube in which the twocomponents are thoroughly mixed as they travel along this nozzle tubebefore being ejected from the outlet end of the tube. Further accordingto the invention, the outlet end of the mixing nozzle tube is fittedwith a rubber adapter piece for fitting into or sealing against theepoxy injection hole 9 of the tooth 2. For example, a piece of ⅜ inchdiameter rubber hose fitted onto the end of the mixing nozzle tube canbe pressed against the surface of the tooth 2 to seal tightly around thehole 9 during the epoxy injection process. Preferably, a tapered rubbernozzle fits and seals into the epoxy injection hole and is fitted ontothe end of the mixing tube. The gun is then operated to inject mixedepoxy 11 under pressure so that the epoxy flows into the gap or voidspace 10 and upwardly along the nose piece 4 until epoxy squeezes out atthe opening of the tooth pocket 2A. This upward flow of epoxy flushesout air upwardly as the epoxy flows and fills all interconnected voidsor gaps. The epoxy squeeze-out is preferably wiped or smoothed to forman epoxy bead or fillet 12 around the body or shank of the nose piece 4at the junction of the nose piece 4 with the tooth 2 around the toothpocket 2A.

Rather than merely relying on the fastener arrangement 5 to hold thetooth 2 on the nose piece 4 while the epoxy cures, the inventionpreferably further provides a special holding clamp arrangement orholding jig 15 as shown in FIG. 4, employed in the method step S8 inFIG. 5. This holding clamp arrangement 15 serves to pull the tooth 2more tightly onto the nose piece 4, and thereby ensures the mostextensive and intimate metal-to-metal contact of the nose piece 4 in thetooth pocket 2A, and also ensures that air voids are squeezed out andthe epoxy forms the thinnest possible void-filling layer between thenose piece 4 and the tooth pocket 2A. The holding clamp arrangement 15also ensures that the tooth 2 is held in a fixed position on the nosepiece 4 while the epoxy 11 cures, and helps to ensure the best possibleadhesive bond of the epoxy with the tooth and the nose piece.

As shown in FIG. 4, the holding clamp arrangement 15 includes a C-clamp17 that clamps onto the front digging edge 3 of the bucket 1. TheC-clamp 17 is preferably embodied as a locking-pliers type C-clamp, forexample a Vise-Grip™ locking C-clamp, but may alternatively be a simpleold-fashioned C-clamp with a screw shaft providing the clamping force tothe clamp jaw pad 17A that clamps onto the digging edge 3 of theexcavator bucket 1. The holding clamp arrangement 15 further comprises atooth bracing or support channel 16 that is connected to the C-clamp 17by a threaded rod 19 and a clevis 18 including a shackle and pin. Anoptional but preferred pressure bracket 20 on the tooth bracing channel16 reinforces it and distributes the force applied by a clampingpressure nut 21 such as a hex nut or wing nut threaded onto the threadedrod 19. The channel 16 is preferably a piece of steel angle with a 90°L-shaped cross-sectional profile, with sufficient length to span twoteeth 2 as shown in FIG. 4. When the clamping pressure nut 21 istightened along the threaded rod 19, the nut 21 presses the pressurebracket 20 against the tooth bracing channel 16, in which the freedigging ends of the two adjacent teeth 2 are supported, so as to pressand hold the teeth 2 tightly onto the nose pieces 4. This tightening bythe holding clamp arrangement 15 will typically produce furthersqueeze-out 12 of the epoxy 11, which is then wiped or smoothed to forma bead or fillet 12 of epoxy as described above. Any epoxy 11 squeezingback out of the injection hole 9 is preferably also wiped off andsmoothed to seal the hole 9. Smoothing off the epoxy squeeze-out to formthe fillet 12 and to seal over the hole 9 is represented in optionalstep S9 in FIG. 5. The holding clamp arrangement 15 is kept in placeuntil the epoxy cures, and is then removed simply by loosening theclamping pressure nut 21 and releasing the C-clamp 17 from the bucket 1.

Once the epoxy has cured, the excavation equipment may be placed backinto service. As discussed above, the epoxy bond and seal between thetooth and the nose piece eliminates or minimizes internal wear of thetooth and wear of the nose piece. When the exterior of the tooth becomesworn to the end of the service range and the tooth needs to be replaced,it is necessary to break the epoxy bond in order to remove the tooth.This can easily be achieved by heating the tooth with a torch, such asan oxygen/acetylene torch with a rosebud heating tip, to a temperaturesufficient until the epoxy fails, for example a temperature of severalhundred to 1200° F. As the metal tooth is heated, the metal expands, andtends to expand away from the epoxy bond, and the heating also causesthe epoxy to crack, fail and crumble. The tooth can then easily beremoved from the nose piece by removing the tooth fastener arrangementand pulling off the tooth. Any remaining epoxy can then be burned,chipped, scraped, sandblasted or otherwise removed from the nose piece.Then a new replacement tooth can be mounted and secured in the abovedescribed manner.

Certain tests and test results in the development of the presentinvention will be described next. Various epoxy formulations were testedfor durable steel-to-steel bonding in preliminary experiments. Theepoxy-based material that was most-recommended for steel-to-steelbonding by a supplier was Devcon® Plastic Steel® Putty No. 10110, whichis a steel-filled epoxy composite material for patching, repairing,rebuilding and bonding all metal surfaces. This epoxy-based material wasmixed and prepared according to the label instructions (9:1 mix ratio byweight, 2.5:1 mix ratio by volume), and was used to install a tooth onan Akerman H-10 excavator, following the above inventive procedureswithout injection of the epoxy material, but rather simply applying theepoxy material into the tooth pocket of the cleaned but otherwiseunaltered tooth. After the epoxy fully cured, the excavator was used fornormal digging operation for approximately 100 hours of use. At thatpoint, the epoxy-bonded tooth had become as loose as it was previouslybefore the application of epoxy. It is thus regarded that the Devcon®Plastic Steel® Putty No. 10110 material does not achieve an adequatebond and is not sufficiently durable for the inventive application.

Another two-component epoxy formulation was obtained and tested. Thisepoxy had a 1:1 mix ratio of the two components, and did not include asteel filler. This epoxy was used to install and secure all eight teethon a John Deere 544 bucket loader. After normal loading use of 45 hourson the John Deere 544 loader, all of the teeth remained tight andsecure, i.e. no teeth showed any looseness or movement. After anotherseven weeks of essentially full time use on the John Deere 544 loader,all of the teeth still remained tight and secure with no movement. After500 hours of use of the John Deere 544 loader, two of the teeth showedsome loose movement, while the other six teeth remained tight and securewith no movement. All of the teeth have remained attached to the nosepieces on the bucket, i.e. no teeth have fallen off.

This epoxy material was also used to install all five teeth of aCaterpillar 330 excavator. After about seven weeks of essentially fulltime use of the Caterpillar 330 excavator, one tooth showed somelooseness and movement, while the four other teeth remained tight andsecure with no movement. After approximately 800 hours of normal diggingoperation with the Caterpillar 330 excavator, three of the teeth showedsome looseness and movement while two of the teeth still remained tightand secure with no movement. All of the teeth have remained attached tothe nose pieces on the bucket, i.e. no teeth have fallen off.

The above epoxy formulation was also used to attach and secure all seventeeth of the Akerman H-10 excavator. After 500 hours of normal diggingoperation, all of the teeth remained tight and secure with no movement.After approximately 600 hours of normal digging operation, two of theteeth began to slightly loosen and show movement, while five of theteeth remained completely tight and secure with no movement. After 900hours of digging use, one tooth remained completely tight and securewith no movement, and six teeth showed some slight movement, but allteeth remained attached, i.e. no teeth had fallen off. Upon removing thesix loose teeth and inspecting the tooth pockets and the nose pieces, itwas subjectively evaluated or judged, based on the inventor's 35 yearsof experience in the excavation field, that the tooth pockets and nosepieces show significantly less wear than would ordinarily be the caseafter 900 hours of use with a conventional mounting method (mechanicalfastening) without the inventive use of epoxy.

The inventor requested changes to the above epoxy formulation so as toincrease the viscosity for making the application process easier, and toincrease the bond strength and inherent material strength of the curedepoxy. The viscosity should be high (thick) enough so that the injectedepoxy will stay in place in the pocket and the fastener hole, and willnot ooze back out through the injection hole or the fastener hole. Onthe other hand, the viscosity should be low (thin) enough so that theinjected epoxy readily flows into and throughout substantially all voidspaces of the tooth pocket under the injection pressure from the manualadhesive injection gun, and will not create too high of a back pressurein the gun which could cause the epoxy components to squeeze past theplungers of the epoxy component cartridges back out of the rear of thegun.

The resultant revised epoxy formulation based on the inventor'srequested modifications is now commercially available as AAS Steelbond™structural adhesive from Advanced Adhesive Systems, 681 North MountainRoad, Newington, Conn. 06111, USA. This epoxy is a 1:1 proportioned,thermosetting, two-component epoxy formulated to have an uncuredviscosity of 250,000 for part A and 220,000 for part B (cps, spindletest TE, 2.5 rpm), an uncured density of 8.07 for part A and 8.05 forpart B (lbs./gallon), an off-white color for part A, an amber color forpart B, and a flash point of 51° F. (LCC). The mixed viscosity is255,000 cps and the mixed density is 8.05 lbs./gallon. The formulationprovides a 10 to 15 minute mixer tube life, a total working time of 15to 20 minutes, a maximum fixture time of 30 to 35 minutes and a typicalfixture time on all surfaces in 20 to 25 minutes or less. The bonds willdevelop 80% cure in two hours, and 100% cure in four hours. The curedmaterial in a steel-to-steel bond provides a high tensile strength of atleast 3,500 psi or optimally greater than 3,800 psi in a tensile sheertest according to ASTM D1002, on metal surfaces in as-received conditionwith no surface preparation. The cured epoxy on sandblasted steel stripsprovides a good peel strength of greater than 40 pli. The epoxy alsoprovides a good impact strength on steel-to-steel bonds, of greater than6.0 joules/in² according to a GMC

Auto Side Impact Test. This adhesive is available in two-component 400ml cartridges, for use in the abovementioned preferred two-componentapplicator guns, and is also available in 5 gallon pails and 50 gallondrums. This AAS Steelbond™ epoxy adhesive has been improved over thepreviously tested epoxy mentioned above, and is considered to be themost preferred adhesive for the present inventive application, althoughit is considered that other epoxy materials of thermosettingtwo-component type without steel filler or without other fillers, andpreferably of 1:1 mix ratio, are also suitable and serviceable accordingto the invention, for example the abovementioned epoxy before theimproving modifications were made.

While the epoxy is suitable for bonding on “as-received” new steelforged parts or machined surfaces, it is further considered that betterbonding will be achieved on excavation equipment tooth pockets and nosepieces (both new and used) by first cleaning those surfaces as describedabove, namely to remove any loose surface dirt, then by degreasing witha solvent to remove any grease or oil, and then by abrasive cleaningwith a sandblasting gun or with a needle scaler or wire brush to providea clean, bare metal surface with a roughened texture and without anypaint, rust, scale or other contaminant residue. The above describedtests were conducted without such cleaning procedures beyond removingdirt. The newest improved and preferred procedure using these cleaningsteps and using the improved preferred AAS Steelbond™ epoxy material wascarried out when removing and reinstalling the six loose teeth of theAkerman H-10 excavator discussed above. Namely, these teeth and theassociated nose pieces were cleaned using sandblasting, and were thenreinstalled using the new improved epoxy material. These six teethremain tight and secure, and the seventh tooth that had been installedusing the previous epoxy formulation without sandblasting also stillremains tight and secure, at the time of filing the present application.

The above tests were carried out on severely worn, used teeth and nosepieces, and demonstrated that the inventive method and combination canbe used to refurbish or retrofit existing used or worn excavationequipment with only cleaning steps as described (and without needing touse new teeth and without requiring the nose pieces to be re-built withhard face welding and grinding). A further test was conducted on aCaterpillar 315 excavator having severely worn, used teeth and nosepieces. The nose pieces were first cleaned as described above. Then theworn surfaces were built up with hard face welding, and the added weldmetal was ground with a grinder to re-shape the surface to near-newspecifications (shape and dimensions). New teeth were then cleaned (inthe tooth pockets thereof) and provided with epoxy injection holes asdescribed above, and mounted on the re-built nose pieces with new pinsand keepers. The preferred formulation epoxy was injected as describedabove to secure the teeth, and the teeth were tightened and held inplace with the holding clamp arrangement, while the epoxy cured. Thenthe excavator was put back into service. All of the teeth remain tightand secure at the time of filing the present patent application. Whileinsufficient digging time has elapsed to validate this, it is expectedthat the best results will be obtained in such an installation startingwith new teeth rather than worn teeth, and with re-built nose pieces (orpreferably new nose pieces) because the most direct metal-to-metalcontact of the nose piece in the tooth pocket is achieved and the epoxymerely needs to provide supplemental support, strengthening and sealingrather than providing a substantial portion of the force transmissionbetween the tooth and the nose piece. Another intermediate option wouldbe to build up the worn nose pieces with excess weld metal and grind thenose pieces to a larger-than-new size and shape to fit the worn interiorpockets of the used teeth rather than replacing the worn teeth with newteeth. The object is to achieve the best reasonably possiblemetal-to-metal fit inside the tooth pockets before injecting the epoxy.

Furthermore, a test was conducted to try to allow easier removal of atooth on which the epoxy was still intact, without requiringtorch-heating of the tooth to break the epoxy. In this regard, a plasticbag was placed into the tooth pocket as a liner and the epoxy was placedinto the bag. Then, the tooth was pushed onto the nose piece in thenormal manner, so that the epoxy surrounded and bonded onto the nosepiece and squeezed-out at the top of the opening of the tooth pocket.The plastic bag, however, isolated the epoxy from the tooth, so that theepoxy did not bond to the interior surfaces of the tooth pock et. Theepoxy was cured and the tooth was put into operation in the normalmanner. This test failed after a short time of digging, in that thetooth became loose, despite the epoxy filling the voids between the nosepiece and the tooth pocket. From this test, it is considered importantthat the epoxy shall bond onto the nose piece and the interior surfacesof the tooth pocket, so as to bond the two components to one another.The epoxy does not merely serve a void-filling function, but also abonding function. This surface bond onto the tooth and the nose piecealso prevents water and grit from corrosively or abrasively wearingsurfaces that would otherwise be exposed. This test also emphasized thatsteps should preferably be taken to enhance the bond of the epoxy ontothe metal surfaces of both the tooth pocket and the nose piece, forexample with the cleaning, degreasing and sandblasting steps describedabove, before introducing the epoxy.

The above tests and test results have shown that the inventiveapplication of an adhesive and preferably a thermosetting two-componentepoxy, and most preferably the specific preferred epoxy mentioned above,for mounting and securing replaceable ground-engaging wear points onnose pieces of excavation equipment, extends the useful operating lifeof the replaceable wear points, because it prevents or reduces loosenessand the resulting interior wear of the teeth and the nose pieces onwhich they are mounted. It thus ultimately prevents or delays the timeat which a tooth must be replaced because it has become too loose orbecause it has fallen off. Inspection of the tooth pockets and nosepieces after conducting the tests has also shown that these surfacesexhibit significantly less wear than would ordinarily be the case if noepoxy had been used according to the inventive method but instead theteeth had been mounted conventionally. The above tests have also shownthat the loss of teeth due to teeth falling off can be prevented ordelayed through the use of the inventive epoxy-mounting of the teeth.

The inventive application of an adhesive and preferably epoxy into theexisting gap or void space in the tooth pocket between the tooth and thenose piece is achieved with simple procedures that can easily be carriedout in the field, with relatively inexpensive materials and tools, andhas been shown to achieve a durable result in normal field use. With theinventive epoxy-mounting arrangement, it is not necessary to provide ametal weld of the tooth onto the nose piece, and it is not necessary toprovide a dirt shield collar or an o-ring seal to try to keep dirt andwater out of the tooth pocket on the nose piece. Thus, the inventivearrangement and method preferably expressly exclude such a weld joint,such a dirt shield collar, and such an o-ring seal.

Although the invention has been described with reference to specificexample embodiments, it will be appreciated that it is intended to coverall modifications and equivalents within the scope of the appendedclaims. It should also be understood that the present disclosureincludes all possible combinations of any individual features recited inany of the appended claims. The abstract of the disclosure does notdefine or limit the claimed invention, but rather merely abstractscertain features disclosed in the application.

What is claimed is:
 1. A combination for mounting a replaceableground-engaging tooth of a ground-engaging tool of a powered excavatingmachine, comprising: a nose piece connected to said ground-engagingtool; a replaceable ground-engaging tooth that has a tooth pockettherein configured and dimensioned to fit on said nose piece, and thatis mounted on said nose piece fitted into said tooth pocket with a gapremaining between said nose piece and said tooth in said tooth pocket; afastening arrangement that mechanically fastens said tooth onto saidnose piece; and an adhesive disposed in said gap and bonding said nosepiece to said tooth in said tooth pocket.
 2. The combination accordingto claim 1, wherein said gap includes a void space between a terminalend of said nose piece and a deepest bottom of said tooth pocket, saidgap further includes a void channel extending from said void space alongsaid nose piece out of said tooth pocket, and said adhesivesubstantially fills said void space and said void channel.
 3. Thecombination according to claim 2, wherein said adhesive furtherprotrudes out of said void space and forms a bead or fillet of saidadhesive along a junction of said tooth and said nose piece at an edgeof said tooth pocket.
 4. The combination according to claim 2, whereinmore than 50% of a surface area of said nose piece in said tooth pocketis in direct metal-to-metal contact with said tooth in said toothpocket, and said gap amounts to less than 50% of said surface area ofsaid nose piece in said tooth pocket.
 5. The combination according toclaim 2, wherein said tooth has a hole penetrating through a tooth wallthereof into said void space in said tooth pocket, and said adhesiveadditionally substantially fills said hole.
 6. The combination accordingto claim 1, wherein said tooth and said nose piece have fastening holestherein aligned with one another, said fastening arrangement includes afixing pin extending through said fastening holes, and an additionalamount of said adhesive is disposed in said fastening holes around atleast said fixing pin of said fastening arrangement.
 7. The combinationaccording to claim 1, wherein said adhesive is a thermosetting epoxy. 8.The combination according to claim 1, wherein said tooth has a holepenetrating through a tooth wall thereof into said tooth pocket at alocation within the deepest 25% of said tooth pocket, and said adhesiveadditionally substantially fills said hole.
 9. The combination accordingto claim 8, further comprising a two-component cartridge adhesiveapplicator gun with a mixing tube, an injection nozzle that is providedat an end of said mixing tube and that fits and is pressed onto or intosaid hole, and a two-component cartridge containing two components thatare ejected and mixed through said mixing tube to produce said adhesive.10. The combination according to claim 1, further comprising a holdingclamp arrangement that includes a clamp clamped onto saidground-engaging tool, a tooth support bracket extending laterally acrossand supporting a free end of said tooth and a free end of anotheradjacent tooth of said ground-engaging tool, a threaded rod connected tosaid clamp and extending through said tooth support bracket, and aclamping pressure nut threaded onto a free end of said threaded rod andtightened to apply a clamping force onto said tooth support bracket. 11.A method of mounting a replaceable ground-engaging tooth of aground-engaging tool of a powered excavating machine, comprising thesteps: a) mounting a replaceable ground-engaging tooth on a nose piecethat is connected to said ground-engaging tool, whereby said nose pieceis fitted into a tooth pocket in said tooth with a gap remaining betweensaid nose piece and said tooth in said tooth pocket; b) installing atooth fastening arrangement that mechanically fastens said tooth a ontosaid nose piece; c) providing an adhesive disposed in said gap andbonding said nose piece to said tooth in said tooth pocket; and d)curing said adhesive.
 12. The method according to claim 11, wherein saidstep c) comprises introducing said adhesive into said tooth pocketbefore said step a), and wherein the subsequent performance of said stepa) causes said adhesive to flow in said gap around said nose piece insaid tooth pocket and to partially squeeze out of said tooth pocketafter substantially filling said gap that remains upon completion ofsaid step a).
 13. The method according to claim 11, wherein said toothhas a hole penetrating through a tooth wall thereof into said gap insaid tooth pocket, and wherein said step c) comprises injecting saidadhesive through said hole into said gap in said tooth pocket after saidstep a).
 14. The method according to claim 13, further comprising,before said step c), an additional step of forming said hole in saidtooth at a location in a deepest 25% of a total depth of said toothpocket and within 1.5 inches of a bottom of said tooth pocket.
 15. Themethod according to claim 11, further comprising, before said steps a),b), c) and d), an additional step of cleaning and degreasing an interiorsurface of said tooth pocket and an exterior surface of said nose piece.16. The method according to claim 11, further comprising, before saidsteps a), b), c) and d), an additional step of cleaning to bare metaland roughening an interior surface of said tooth pocket and an exteriorsurface of said nose piece using a procedure selected from the groupconsisting of sand or grit blasting, needle scaling using a poweredneedle scaler, and brushing using a powered wire brush.
 17. The methodaccording to claim 11, wherein said tooth fastening arrangement includesa fixing pin, said step b) comprises inserting said fixing pin intoaligned holes present in said tooth and said nose piece afterperformance of said step a), and said method further comprises a step ofinjecting an additional amount of said adhesive into said aligned holesbefore or after said step b) such that said additional amount of saidadhesive at least partly surrounds said fixing pin after said fixing pinis inserted in said aligned holes.
 18. The method according to claim 11,wherein said adhesive partially squeezes out of said tooth pocket at ajunction where said nose piece enters said tooth pocket, and furthercomprising smoothing said squeezed-out adhesive to form a fillet of saidadhesive along said junction or applying an additional bead of saidadhesive along said junction.
 19. The method according to claim 11,wherein said adhesive is a thermosetting, curing, two-component epoxy.20. The method according to claim 11, further comprising an additionalstep of clamping a holding jig onto the ground-engaging tool, and aftersaid steps a), b) and c) tightening said holding jig to apply a forceonto said tooth in a direction pressing said tooth onto said nose piece,and maintaining said force during said step d).
 21. A replaceable toothfor a powered excavation machine, comprising a tooth body bounding atooth pocket therein, wherein said tooth body has a hole penetratingthrough a tooth wall thereof into said tooth pocket at a location in adeepest 25% of a total depth of said tooth pocket and within 1.5 inchesof a bottom of said tooth pocket.